A wide paper reel coming from a paper machine is first of all taken to a slitter-winder and cut into customer reels of a suitable width. Next, the reels are packaged for transporting. When packaging paper reels, inner end shields are first of all placed on their ends, after which the necessary amount of wrapping is wrapped around them, the ends of which are folded on top of the inner end shields on the ends of the reels. An outer end shield is usually glued by hot sealing on top of the folded end of the wrapping and the inner end shield. The inner end shield is usually quite thick and its task is to protect the end of the reel from mechanical damage. For its part, the outer end shield is thinner and its task is to hold the packaging onto the end of the reel and to protect the reel from moisture. Colouring and patterns are often used on the outer end shield to try to give the reel a tidy appearance. The length and diameter of the reel to be packaged are measured prior to packaging and on the basis of the measurement results end shields of a suitable size are selected for the reel ends. A reel packaging line usually comprises several consecutive stations, by means of which the necessary operations are performed. Reels are moved between stations by a conveyor or by rolling.
The end shields can be placed on the end of the reels in many different ways. Placing the shield by hand is the oldest method and one that is still suitable for packaging lines with a reasonably small capacity, or in installations in which there is no need to increase the degree of automation. The packer then simply places the inner shields by hand on the ends of the reel and the outer shields correspondingly on the heat-pressing plates, which press the outer shields onto the ends of the reel. The inner shields can also be transferred by an air blast or by hand without mechanical contact. The inner shields are held on the end on the reel on a separate arm, or by an air blast while the edges of the wrapping are folded. The outer shields are, in turn, attached to the press plates by vacuum suction and are pressed onto the ends of the reel using the press plates. When setting the shields by hand, the packer ensures that shields of the correct size are put on the reel and that they are positioned correctly.
Various kinds of automatic end-shield setters have already been used for a long time and several different kinds of them exist. Nearly all the automatic shield setters have the common feature that at each end of the reel there is a device comprising a grab, which transfers a shield from the stack of shields to the end of the reel. In one known shield setter, there is a rotating arm mounted on a vertical guide, at the end of which arm there is a rotating vacuum sucker for gripping the shields. Shield setters of this kind are normally used in conjunction with racks of shield shelves located next to the setter. Using such a device, the shields are placed on the end of the reel, in such a way that the arm of the grab is moved along the vertical guide to the height of the shelf on which there are end shields of the correct size. The grab arm and sucker are turned, until the sucker is aligned parallel to the plane of the shelf, after which the shield is picked up from the shelf and the arm and sucker are moved to the reel end by rotating them and moving them along the guide. Instead of shelves, the end shields can be placed in stacks on the mill floor, or in a rotating shield magazine.
Instead of the aforementioned manner of handling end shields, a standard-model industrial robot with several degrees of freedom can be used to handle shields. A robot of this kind can be located in connection with the wrapping station, in such a way that it can place an end shield on both ends of the reel. The efficient operation of the robot requires a two-sided grab to be used, by means of which the grab can be rotated to pick up shields for both ends can be picked up one after the other, so that two lifting movements will not be required. It is also possible to use two robots to achieve a shorter cycle time.
End shields can also be placed on the reel ends from stacks on the mill floor, by using portal-action shield setters. The transfer portal is constructed above the shield stacks and the shield setters are generally installed on the same transverse movable guide. There is a separate shield setter for each side of the reel and each shield setter must have its own stack of end shields of a specific size. The end-shield stacks are placed in a matrix pattern on the floor of the mill hall.